Sympathetic cardiovascular control during orthostatic stress and isometric exercise in adolescent chronic fatigue syndrome

Abstract

The chronic fatigue syndrome (CFS) has been shown to be associated with orthostatic intolerance and cardiovascular dysregulation. We investigated the cardiovascular responses to combined orthostatic stress and isometric exercise in adolescents with CFS. We included a consecutive sample of 15 adolescents 12-18 years old with CFS diagnosed according to a thorough and standardized set of investigations, and a volunteer sample of 56 healthy control subjects of equal sex and age distribution. Heart rate, systolic, mean and diastolic blood pressure, stroke index, and total peripheral resistance index were non-invasively recorded during lower body negative pressure (LBNP) combined with two consecutive periods of handgrip. In addition, we measured baseline plasma catecholamines, and recorded symptoms. At rest, CFS patients had higher heart rate, diastolic blood pressure, plasma norepinephrine (P < 0.01), mean blood pressure and plasma epinephrine (P < 0.05) than controls. During LBNP, CFS patients had a greater increase in heart rate, diastolic blood pressure, mean blood pressure (P < 0.05) and total peripheral resistance index (n.s.) than controls. During handgrip, CFS patients had a smaller increase in heart rate, diastolic blood pressure (P < 0.05), mean blood pressure and total peripheral resistance index (n.s.) than controls. Our results indicate that adolescents with CFS have increased sympathetic activity at rest with exaggerated cardiovascular response to orthostatic stress, but attenuated cardiovascular response when performing isometric exercise during orthostatic stress. This suggests that CFS might be causally related to sympathetic dysfunction.

Postural Orthostatic Tachycardia Syndrome (POTS) and Vitamin B12 Deficiency in Adolescents

“…31 Other studies have demonstrated that the change of posture may lead to an abnormal cardiovascular response (orthostatic hypotension, POTS, syncope) in one-third of patients 32,33 and that CFS is most likely associated with sympathetic dysfunction. 34 There are also studies supporting the similarity of the autonomic dysfunctions observed in CFS and POTS. 35,36 Hägglöf 37 in 2000 and Björkegren 38 in 1999 demonstrated that CFS could be treated with vitamin B 12 .…”

Chronic fatigue syndrome in 57-year-old woman

“…Although some authors suggest that the response of CFS patients to passive verticalization is similar to that of healthy individuals, it has been shown that the activation of the sympathetic nervous system can be more pronounced as was documented in our patient [15][16][17][18][19][20][21][22][23]. The evaluation of chronic fatigue syndrome remains challenging.…”

Is fatigue in Marfan syndrome related to orthostatic intolerance?

“…Treatment of orthostatic intolerance symptoms with fludrocortisone, however, in all studies did not reduce symptoms of fatigue in patients with chronic fatigue syndrome [2,22]. Recently, studies on the increased sympathetic activity in patients with chronic fatigue and orthostatic intolerance were published, suggesting a possible beneficial role for beta-blockers in this patient group [36,37]. These, and other treatment options, still have to be studied in this specific patient group.…”